How to extend the life of a printhead on a label printer
Printheads are the most common repair on a thermal printer, and can run as much as 30% of the cost of a new printer, depending on the printhead resolution. Wouldn’t it be great to increase the printhead life to as much as two or three times the life the manufacturer expects?
Here are some tips to help extend the life of your printhead.
Your print head life expectancy is affected by five factors:
Ribbon Residue If you use thermal transfer labels (labels that require a ribbon), you will use a thermal or roll ribbon. Thermal ribbons leave a residue. After each ribbon, it’s recommended you clean the printhead with an alcohol pad containing 95% isopropyl alcohol. This will remove the residue from the head.
Paper dust from the label Your labels, like any paper product, contain paper dust that is abrasive to the printhead. This dust needs to be removed so that the head is not scratched over time. Once again, cleaning the printhead with an alcohol pad containing 95% isopropyl alcohol will remove the paper dust along with the ribbon residue. If you use direct thermal labels (labels that do not require a ribbon), it is even more important to clean the heads. Since you are not using a ribbon, which has a smoother coating than the face of a paper label, the label is more abrasive to the printhead surface. Keeping the surface clean will more than double the life of the head.
Print speed and temperature settings -The speed you select to run your labels changes the printhead temperature. The faster you print, the higher the temperature required to maintain resolution. In your label creation software, you can select the print speed of the printer and the heat setting of the printhead. All thermal printers like Zebra, Sato or Datamax have print speeds of up to 12 inches per second, depending on your model. The question you should ask is, “Do I need all that speed for my application?” If you are printing a few labels at a time or even large batches, try running at half the printer speed. That may be 5 or 6 inches per second, which is still very fast!
Printhead Temperature – Just as speed controls printhead temperature, the printhead temperature controls print quality. Here are some things you need to know:
Direct thermal labels require higher printhead temperatures. That will shorten printhead life. Wax ribbons require lower printhead temperatures than resin ribbons. Higher printhead temperatures will give you better resolution, but too high will greatly shorten printhead life.
The higher the temperature – the more strain you will put on the printhead. So when you create a new label format, make sure you test the print quality and set the temperature at the lowest temp where you see the level of acceptable quality.
Physical environment of the printer- Straight white lines or print head voids -If there is a straight white line on your labels, you have a VOID in your printhead. That means one or more of the diodes or dots on the head are no longer functioning. That could mean time to get a new print head, especially if it is altering a line on your bar code.
User Damage – Don’t ever use any object like a razor blade to remove a barcode label or any residue that is sticking to the head. You could damage or destroy the electric diodes that bring heat to the label or ribbon surface. Again, use an alcohol pad with a high concentration of isopropyl alcohol to remove adhesive residue, or call a trained professional.
How to clean a Printhead on a label printer
1. Turn off and unplug the printer. Allow the print head to cool.
2. Raise the media door.
3. Open the print head. There is typically a lever or latch that you raise to do this.
4. Remove the labels and ribbon.
5. Use a cleaning swab or a cotton swab moistened with isopropyl alcohol and wipe the print elements from end to end. (The print elements are the grayish/ black strip just behind the chrome strip on the underside of the print head.) Wait a few seconds for the solvent to evaporate.
6. Clean the platen roller thoroughly with a cleaning swab. Rotate the roller to get all its sides.
7. Brush away or vacuum any paper lint and dust away from the rollers and the media and ribbon sensors.
8. Reload ribbon and/or labels.
9. Close the printhead by lowering the lever or latch until it locks in place.
10. Close the media door.
Label Printer - Which is better direct thermal or thermal transfer?
To help decide whether to select a direct thermal printer or thermal transfer printer consider the following questions:
Will you ever need to print labels in colors other than black?
Do the labels need to be scanned or have a shelf-life of over 1 year?
Will you be printing high density bar codes (i.e. limited space)?
Will the labels be subjected to heat or sunlight?
Will the labels be prone to abuse or surface friction?
Will you be printing on a variety of different substrates (i.e. papers, films and foils)?
If you answered “yes” to any of the above questions then you should consider going thermal transfer rather than direct thermal.
Here are some printer comparisons:
Thermal transfer printers
Thermal transfer label printers require the use of a carbon ribbon which gets transferred onto the substrate via heat, hence the name “thermal transfer.” The ribbons can be different colors, so the user is not limited to black print. The printing is very crisp and durable so this method is excellent for high density bar codes and labels that require longevity.
The other benefit is that thermal transfer printers can print on paper, film, and even foil substrates. Please note that the proper selection and match of label stock and ribbon is critical to the overall quality and performance of printed media.
Direct thermal printers
Direct thermal printers require the use of heat activated thermal papers and films, but require no transfer ribbon. The print color is limited to black, unless special, preprinted direct thermal paper is utilized, and the printing is not as crisp as that of thermal transfer ribbon printing. Over time the labels will darken, particularly when the surface gets scratched, or is subjected to heat and sunlight.
However, a true direct thermal label printer utilizes a print head that is made of thicker glass, for increased print head durability. Direct thermal printing is popular in the food industry, since most items are stored away from heat and sunlight, and the label shelf life is less than 1 year. The primary benefit is an overall lower cost and easier media changeovers since ribbon is not required
How to calibrate a Zebra Printer?
There are two types of media (label) calibration procedures on the Zebra printer. Sometimes there is a misunderstanding on which calibration procedure to perform and when to do it. The following will explain the differences. The first calibration is used to calculate the current label length installed in the printer. This procedure is used primarily when changing from one label length to another or when there is an inconsistent registration problem with the label.
Perform the following steps:
- Set the label length in the Setup Menu to 1 inch larger than the labels installed currently in the printer, then exit the menu and save the setting.
- Press the Pause key, then the Calibrate key on the front panel. Once the Calibrate key is pressed the printer will advance 2-3 labels then stop. At this point the label length is calibrated.
- Press the feed key to make sure only one label at a time is advanced.
- The second calibration procedure is used to adjust the sensitivity of the media sensor. This procedure is usually performed when there are “out of label” faults occurring or when a different type of media (label stock) is installed in the printer. To perform this calibration procedure:
- Go to the Setup Menu and scroll until the menu reads MEDIA AND RIBBON CALIBRATE.
- Press the right arrow key on the printer to start the procedure.
- Follow the prompts on the LCD display step by step.
Note: Make sure the upper and lower sensors are aligned, as well as clean, before performing the calibration procedures.
How to calibrate media & ribbon for a Zebra Printer?
Use this procedure to adjust sensitivity of media and ribbon sensors.
Note – Before you begin this procedure, make sure that the maximum length is set to a value equal to or greater than the length of the labels you are using. If the maximum length is set to a lower value, the calibration process assumes that continuous media is in the printer
Important – This procedure must be followed exactly as presented. All of the steps must be performed even if only one of the sensors requires adjustment. You may press the minus key at any step in this procedure to cancel the procedure.
1. Press the plus key to start the calibration procedure. The LOAD BACKING prompt displays.
2. Open the printhead.
3. Remove approximately 8 in. (203 mm) of labels from the backing, and pull the media into the printer so that only the backing is between the media sensors.
4. Leave the printhead open.
5. Press the plus key to continue. The REMOVE RIBBON prompt displays.
6. Remove the ribbon.
7. Close the printhead.
8. Press the plus key to continue. The message CALIBRATING PLEASE WAIT displays. The printer adjusts the scale (gain) of the signals that it receives from the media and ribbon sensors. On the sensor profile, this essentially corresponds to moving the peak of the graph up or down to optimize the readings for your application. When calibration is complete, RELOAD ALL displays.
9. Open the printhead and pull the media forward until a label is positioned under the media sensor.
10. Reload the ribbon.
11. Close the printhead.
12. Press the plus key to continue. The printer does a calibration equivalent to pressing CALIBRATE; during this process, the printer determines the label length. To see the new readings on the new scale, print a sensor profile.
How to choose a barcode label printer
When choosing a barcode label printer for your business, it’s important to remember that not all types of printers are created equal. While dot matrix, ink jet, and laser printers may be capable, at least in theory, of creating scannable barcode labels, in most cases questions about lifetime ownership costs, ease of use, and barcode quality arise.
When barcode labels are printed, the tolerances are quite tight, with the width of bars, spaces, and quiet zones measured in thousands of an inch or mils. If bar widths are inconsistent or the contrast between light and dark elements is lacking, the barcode label won’t be read.
That’s why most companies use thermal printers for their barcode labeling needs. These printers are capable of printing one or a thousand barcode labels at a time, with the highest print sharpness and quality. And since barcode labels are needed wherever products are kept, printers must be able to stand up to harsher conditions than the normal office environment.
What to ask when shopping for a barcode label printer
Finding the right barcode label printer requires an individualized approach. These questions will help you look at your own processes and needs a little more closely.
- What’s the expected barcode label print volume?
- Will labels be printed in batches or on-demand?
- What size label will be used?
- How important is print quality? What will happen if barcode label can’t be read?
- If label requirements change, can modifications be made internally or will outside support be required?
- How often will barcode label printers need to be replaced or repaired?
- Can the suggested printer stand up to the environment where labels are needed?
- How much ongoing IT support and operator time is needed to run and maintain the system?